"text processing operator does not run in Ubuntu"

hi,

We have written a Java program to execute set of rapidminer command through rmp file to process text file into word vector using TF-IDF, stemming and etc. This program works fine in Windows environment but when we port it to Ubuntu, it gave the following error message:

com.rapidminer.operator.UserError: The dummy operator Read Doucment (replacing text:read_document) cannot be executed.
  at com.rapidminer.operator.DummyOperator.doWork(DummyOperator.java:88)
  .....


The following is the Java code:
RapidMiner.init();
Process pr = new Process(new File("/home/administrator/test/process/newp/C.rmp"));
try {
pr.run();
} catch (OperatorException e) {
e.printStackTrace();
}


We have given all the read-write access to the files and directory.
We also tried adding the following before the RapidMiner.init() but nothing seems to work.
                        RapidMiner.setExecutionMode(ExecutionMode.COMMAND_LINE);
Plugin.setInitPlugins(true);

Really appreciate your guidance and advice.